public class Main {
    public static void main(String[] args) {
        String book1 = "红楼梦";
        String book2 = "三国演义";
        System.out.println(book1+book2);
        char a1 = '男';
        char a2 = '女';
        System.out.println(a1+a2);
        double price1 = 100.0;
        double price2 = 145.78;
        System.out.println(price1+price2);
    }
}